Recording/reproducing apparatus using an IC memory

ABSTRACT

A recording/reproducing apparatus using an IC memory includes an IC memory to/from which writing/reading of an audio signal is performed; and a control circuit for controlling writing/reading of the audio signal to/from this IC memory, and its address, and for controlling, on writing and reading the audio signal to and from the IC memory, so that its address becomes ring-shaped, writing, of when a recording key is pressed, the audio signal from contiguous address to an area, within the IC memory where the writing, which has never been read is performed, and reading, of when a reproduction key is pressed, the audio signal from the head of an area within the IC memory where the writing, which has never been read, is performed.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an IC recording/reproducing apparatus.

2. Description of Related Art

There is an IC in which a memory is used as a recording medium for audiosignals, and the memory, a recording circuit and a reproducing circuitare incorporated into one chip. Such an IC cannot carry out recordingfor a long time unlike a tape recorder, but can carry out recording forseveral minutes. This is therefore suitable for simply recording such abrief message as a memo, i.e., a matter of business or the like.

If a memory, is used the recording medium records and reproduces signalsin address order in the structure of the address management.

For this reason, it is necessary to manage records by assigning a numberto each of matters of business recorded among others and to erase anyunnecessary matters of business in accordance with this managementinformation, and therefore, the operations become complicated. Also,even if there are some matters which may be erased, the recording timewill not belong unless they are erased in advance.

SUMMARY OF THE INVENTION

The present invention intends to solve these problems. For this reason,the present invention provides an IC recording/reproducing apparatus,comprising:

a memory to/from which writing/reading of an audio signal is performed;and

a control circuit for controlling writing/reading of the audio signalto/from this memory, and its address,

the control circuit controlling, so that on writing and reading theaudio signal to and from the memory, its address becomes ring-shaped,

writing, of when a recording key is pressed, the audio signal from anaddress contiguous to an area within the memory where the writing, whichhas never been read, is performed, and

reading, of when a reproduction key is pressed, the audio signal fromthe head of an area within the memory where the writing, which has neverbeen read, is performed.

Therefore, on recording, no overwriting is performed on any matterswhich have not yet been reproduced, but a new matter is overwritten onmatters which have been reproduced even once. Also, on reproducing, amatter which has not yet been reproduced is preferentially reproduced.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a system circuit block diagram showing an embodiment accordingto the present invention;

FIG. 2 is a flowchart showing a part of an embodiment according to thepresent invention;

FIG. 3 is a flowchart showing a part of an embodiment according to thepresent invention;

FIG. 4 is a flowchart showing the embodiment continued from FIG. 3;

FIG. 5 is a view showing an embodiment of a data table;

FIG. 6 is a schematic view for explaining the present invention; and

FIG. 7 is a schematic view for explaining the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

To record a matter generally presupposes a condition that it will bereproduced later. Namely, a matter which has been once recorded will beheard at least once.

In the present invention, assuming as follows:

An unreproduced matter: a matter which has not yet been reproducedalthough recorded, and

A reproduced matter: a matter which has been reproduced at least onceafter recorded. The unreproduced matter is distinguished from thereproduced matter. On recording a new matter in the memory, overwriterecording is allowed for the reproduced matter, but is prohibited forthe unreproduced matter.

Also, in order to efficiently use a recording area for a unreproducedmatter and a recording area for a reproduced matter on the memory, theaddress of the memory is made into a ring-shape.

In other words, in FIGS. 6 and 7, reference numeral 1 schematicallydesignates addresses and the recording messages (matters) of a memoryfor recording and reproducing a matter, and the addresses are madering-shaped as described above. In the ring-shaped addresses, theaddresses shall be used in a clockwise direction on recording andreproducing.

It is assumed as shown in FIG. 6A that four matters {circle around (1)},{circle around (2)}, {circle around (3)} and {circle around (4)} arerecorded in this order in the memory 1 and the matters {circle around(1)} and {circle around (2)} are reproduced matters (these are indicatedby “finished”) while the matters {circle around (3)} and {circle around(4)} are unreproduced matters (these are indicated by “unfinished”). Inthis respect, the remaining area may be either a non-recorded area or areproduced area.

In a case where the matters of the memory 1 are in such a state, whenthe reproduction key is pressed, the oldest unreproduced one of theunreproduced matters at this point of time, i.e., the matter {circlearound (3)} is started from its head for reproducing as shown in FIG.6B. After the matter {circle around (3)} is reproduced as shown in FIG.6C, the reproducing is terminated then, and a stop state is reached.Accordingly, at this point of time, the matter {circle around (3)}becomes a reproduced one.

When the reproduction key is pressed again in the state shown in FIG.6C, the matter {circle around (4)}, which is the oldest unreproduced oneof the unreproduced matters at this point of time, is reproduced fromits head.

If there are thus any unreproduced matters, the oldest unreproducedmatter of those will be reproduced from its head, and after the matteris reproduced, the reproducing will be automatically stopped.

On the other hand, when the recording key is pressed with the matters inthe memory 1 in such a state as shown in FIG. 7A (this is the same asFIG. 6A), the newest unreproduced one of the unreproduced matters atthis point of time as shown in FIG. 7B is the matter {circle around(4)}, and the recording starts from the next address thereto.

When the stop key for recording is pressed before the recording reachesthe area {circle around (1)} as shown in FIG. 7C, the recording isstopped there. Therefore, at this time, the area contiguous to thematter {circle around (4)} becomes a new unreproduced matter {circlearound (5)}, and at the same time, includes a newer matter recorded thanthe matter {circle around (4)}.

When the stop key for recording is not pressed even if the recordingreaches immediately before the area in which the matter {circle around(1)} has been recorded, the recording is continued by overwriting to thearea for the matter {circle around (1)} as shown in FIG. 7D. When thestop key for recording is pressed during the recording, the recording isstopped there. Therefore, an unreproduced matter {circle around (5)} isto be recorded to extend over between the next one to the matter {circlearound (4)} and the previous matter {circle around (1)}.

Further, when the stop key for recording is not pressed even if therecording is performed on the entire area for the matter {circle around(1)}, the recording is continued by overwriting also to the area for thematter {circle around (2)}. When the stop key for recording is pressedwhile the recording is being performed on the area for this matter{circle around (2)}, this is the same as in FIG. 7D, and the recordingis stopped there and the recording becomes a new matter {circle around(5)}.

When the stop key for recording is not pressed even if the recordingreaches the last of the area for the matter {circle around (2)}, thenext recording area is the area for the unreproduced matter {circlearound (3)}, and therefore, the recording is automatically stopped infront of the area for the matter {circle around (3)}.

In this respect, since recording and reproducing are performed asdescribed above, the description on recording or reproducing from thestate of FIG. 6A or FIG. 7A shows all cases even if the state of FIG. 7Ais different from that of FIG. 6A in numbers of unreproduced matters andreproduced matters.

In the present invention, recording and reproducing are performed inaccordance with the above-described procedures or rules.

Hereinafter, the description will be made of an embodiment when thepresent invention is applied to an IC recording/reproducing circuitincorporated in an AM receiver.

FIG. 1 is a block diagram showing an IC recording/reproducing circuitincorporated in an AM receiver, and a reception circuit 11 for receivingAM broadcasting connected to a bar antenna 10 includes the circuits froman antenna input circuit to an AM detection circuit, and is constitutedaccording to the superheterodyne system. Further, this reception circuit11 is constituted according to the synthesizer system, and oscillationsignals from VCO of PLL are used as local oscillation signals. Bychanging the dividing ratio of a PLL variable dividing circuit, thelocal oscillation frequency is changed to change the receptionfrequency.

On receipt of broadcasting, a broadcasting audio signal is taken outfrom the reception circuit 11, and this audio signal is supplied to aspeaker 16 through a switching circuit 14 and an amplifier 15 which areconnected as shown in the figure during reception of broadcasting.

Reference numeral 12 designates a built-in microphone, and referencenumeral 20 designates a recording/reproducing circuit. In this case, therecording/reproducing circuit 20 comprises an IC incorporated into onechip, and in this example, the recording/reproducing circuit 20 does notconvert an audio signal into digital data, but records and reproduces itwith the analog signal remaining as it is. For this reason, therecording/reproducing circuit 20 consists of a low-pass filter 21, amemory 22, a low-pass filter 23, a control circuit 24, and a clockforming circuit 25.

The filter 21 performs anti-aliasing process of an audio signal to berecorded. Further, the memory 22 samples audio signals from the filter21 at a predetermined frequency to store onto each address in order foreach sample on writing, and on reading, fetch, from each address, thesamples written therein in sequence to output audio signals. The filter23 performs a smoothing process of an audio signal fetched from thememory 22.

The control circuit 24 controls writing/reading of audio signals to/fromthe memory 22, and their addresses. When a command RECPWR forinstructing to stand ready for writing and an address A ADR aresupplied, the control circuit 24 stands ready in a state to startwriting at an address A ADR of the memory 22, and when a command RECDfor indicating permission for writing is supplied, the control circuit24 starts the writing at the address A ADR.

When a command PLAYPWR for instructing to stand ready for reading and anaddress A ADR are supplied, the control circuit 24 stands ready in astate to start reading at the address A ADR of the memory 22, and when acommand PLAYDD or indicating permission for reading is supplied, thecontrol circuit 24 starts reading at the address A ADR.

When writing or reading has advanced to the last address to or from thememory 22 on writing and on reading, data OVR indicating thisadvancement is outputted from the control circuit 24. When on reading,the reading has advanced to the last address where the writing wasperformed, data EOM indicating this advancement is outputted from thecontrol circuit 24.

When a command STOP for instructing to stop is supplied while writing orreading is being performed to or from the memory 22, the writing orreading is stopped. In this respect, since a start address A ADR forwriting to the memory 22 and termination of the writing can beoptionally set or controlled as described above, a plurality of mattersor messages (audio signals) can be stored in one memory 22.

Further, the control circuit 24 also controls the power supply state forthis recording/reproducing circuit 20, i.e., the IC 20, and when acommand STOPPWRD is supplied while the IC 20 is in an activated state,the IC 20 is caused to be in a standby state, and stands ready for anext effective command with almost no consumption of electric current.When a command POWERUP is supplied while the IC 20 is the standby state,the IC 20 is caused to be in an activated state, and comes to accept acommand RECPWR, PLAYPWR for recording or reproducing (write or read) asdescribed above.

In this respect, as an IC 20 capable of recording and reproducing asdescribed above, there are, for example, ICs of ISD33000 series producedby ISD Corp. One of these ICs has the following specifications: thesampling frequency when audio signals are recorded on the memory 22 is6.4 kHz, the cut-off frequency of filters 21 and 23 is 2.7 kHz, and themaximum recording time is 150 seconds. In the IC of the same series, thememory 22 is a nonvolatile memory, and it is not necessary to create anybackup copies even when the power supply is turned off.

Reference numeral 40 designates a microcomputer for system control, andas this microcomputer, a 4-bit microcomputer μPD17073 produced by NECCorporation was used. This microcomputer 40 is prepared by incorporatingthe following into one chip: a CPU 41, a ROM 42 having a program forcontrolling this receiver written therein; a RAM 43 for a work area; aninput port 44 and an output port 45; and the like.

The ROM 42 is, as a part of a program written therein, provided with,for example, a recording routine 100 shown in FIG. 2 and a reproducingroutine 200 shown in FIGS. 3 and 4. In this respect, the details onthese routines 100 and 200 will be described later.

Further, since the physical address of the memory 22 is not ring-shaped,the address of the memory 22 is made ring-shaped by the use of theprogram for the ROM 42. More specifically, when the writing or readingreaches the last address of the memory 22 on recording or onreproducing, data EOM indicating this is outputted from the controlcircuit 24, and therefore, the microcomputer 40 monitors the presence orabsence of this data EOM on recording and on reproducing.

When the data EOM is outputted, a command RECPWR or PLAYWR for standingready for writing or reading and its start address A ADR are suppliedfrom the microcomputer 40 to the control circuit 24, and subsequently, apermission command RECD or PLAYDD for writing or reading is supplied.

Therefore, when writing or reading is executed up to the last address ofthe memory 22 on recording or on reproducing, the writing or the readingis continued at an address indicated by the start address A ADR, and thememory 22 becomes ring-shaped.

Furthermore, the ROM 42 is provided with a frequency table forbroadcasting stations. More specifically, if this receiver is destinedfor Japan, the whole of Japan is divided into, 14 regions such as“Hokkaido” to “Kyushu” districts in accordance with the reception statusfor broadcasting, and in the frequency table, data on frequencies for AMbroadcasting stations can be received respectively in each region thusdivided. For example, the dividing ratio of PLL is provided for eachregion.

The microcomputer 40 is connected to a memory 51 outside. For thismemory 51, a ROM capable of electrically erasing and writing data isused, or a RAM which is backed up by a battery although not shown isused, in other words, for the memory 51, a nonvolatile memory is used sothat any data written can be retained even when the power supply isturned off. Also, as data on reception frequency for station selection,the memory 51 is adapted to store the dividing ratio and the like of PLLvariable dividing circuit for the reception circuit 11.

When the recording/reproducing circuit 20 has such standards orspecifications as described above, the start address A ADRS for writingand reading (recording and reproducing) of the memory 22 can bedesignated, but the microcomputer 40 is not capable of knowing anaddress at the termination of the writing and reading.

For this reason, in this example, the memory 51 is provided with amanagement table RECT for managing the address for the memory 22 asshown in, for example, FIG. 5. In this management table RECT, theaddress area for the memory 22 is divided into a plurality of areas, andthe divided areas are managed as units. More specifically, the addressarea for the memory 22 is divided into n pieces of areas X A1 to X An,for example, an area for 1 second at a time, and when the respectivehead addresses of the divided areas X A1 to X An are assumed to beaddresses A ADR1 to A ADRn, the management table RECT has 1 set each oftheir head addresses A ADR1 to A ADRn, head flags BGN1 to BGNn, andunreproduced flags UPB1 to UPBn corresponding to areas X A1 to X An.

In this case, if it is assumed that a matter has been recorded in, forexample, divided areas X A2 to X A5, the divided area X A2 becomes afirst area used for the recording, and therefore, a head flag BGN2corresponding to this area X A2 is set to “1” while head flags BGN3 toBGN5 corresponding to other areas X A3 to X A5 respectively are causedto be “0”. Namely, when a certain matter is recorded in the memory 22, ahead flag BGNk corresponding to the first divided area X Ak (k=any of 1to n) used for recording the matter is set to “1”, and head flagscorresponding to other divided areas used for the recording are causedto be “0”.

Therefore, by checking the head flags BGN1 to BGNn, it can be seenwhether or not a divided area corresponding thereto is the first dividedarea used for recording the matter. Each divided area X A1 to X An isclassified by head addresses A ADR1 to A ADRn.

Unreproduced flags UPB1 to UPBn show whether or not their correspondingdivided areas X A1 to X An are unreproduced ones, and if a certaindivided area has never been used for reproducing after recorded, thecorresponding unreproduced flag UPNk is “1”, and if it has been usedeven once for reproducing, the corresponding unreproduced flag UPBk iscaused to be “0”.

Further, to the microcomputer 40, there are connected a LCD 52 as adisplay for displaying various information such as a receptionfrequency, and various operation keys K PW to K PB and, for example,seven station selection keys K1 to K7. In this respect, these operationkeys K PW to K PB and station selection keys K1 to K7 are allconstituted by non-lock type push switches.

In such structure, when the CPU 41 executes a program of the ROM 42, therespective processes and operations are executed as below.

[On/Off of Power Supply]

As regards the power supply unit, On and Off of the power supply arealternately repeated every time a power key K PW of the operation keys KPW to K PB is pressed. When the power supply is off, the operatingvoltage is supplied only to the microcomputer 40, which is in a standbystate. When the power supply is on, the power supply is supplied to allthe circuits, but the recording/reproducing circuit 20 is in the standbystate.

[Presetting of Broadcasting Station]

This is a case of presetting a broadcasting station to station-selectionkeys K1 to K7. In this case, an area key K AE of the operation keys K PWto K PB is pressed when the power supply for the receiver is on.

Every time the area key K AE is pressed, the region names obtained whenthe whole of Japan was divided into 14 regions are displayed on the LCD52 in turn, and data on frequencies of those broadcasting stations canbe received in the region displayed. In this case, the dividing ratio isread from the frequency table for broadcasting stations which the ROM 42has and the dividing ratio thus read is written in the respective areasof the data table of the memory 51.

Therefore, by only selecting the name of a region including a placewhere the receiver is used, those broadcasting stations which can bereceived in the region are to be preset to any of the station-selectionkeys K1 to K7.

[Station Selection by a Station-Selection Key]

This shows a case where broadcasting stations preset to thestation-selection keys K1 to K7 are selected. In this case, of thestation-selection keys K1 to K7, any station-selection key Ki (i=any of1 to 7) is pressed when the power supply for the receiver is on.

Then, of the data table for the memory 51, from an area corresponding toa station-selection key Ki thus pressed, the dividing ratio writtenthere is read, and this dividing ratio is set to the PLL variabledividing circuit for the reception circuit 11. Accordingly, thereception frequency for the reception circuit 11 becomes a frequencycorresponding to the station-selection key Ki pressed, and abroadcasting station preset to the station-selection key Ki is selected.

Therefore, when any of the station-selection keys K1 to K7 is pressed,the broadcasting station preset to the station-selection key Ki can beselected, and it is possible to listen to the broadcasting.

[Manual Station Selection]

This shows a case where the user selects a frequency by a keyingoperation to select a station. In this case, a plus key K+ or a minuskey K− of the operation keys K PW to K PB is pressed when the powersupply for the receiver is on.

Then, the dividing ratio for the PLL variable dividing circuit of thereception circuit 11 is incremented or decremented, for example, by 1every time the plus key K+ or the minus key K− is pressed, and as aresult, the reception frequency is raised or decreased by 9 kHz eachtime. The reception frequency at the time is displayed on the LCD 52.Thus, when a desired reception frequency is reached, the reception stateof the reception frequency will continue thereafter if the operation ofthe plus key K+ or the minus key K− is stopped.

Accordingly, by pressing the key K+ or K−, the station can be selectedat any reception frequency.

[Recording of voice by Microphone]

This shows a case where voice on a matter or the like is recorded usingthe microphone 12. In this case, a recording key K RE of the operationkeys K PW to K PB is pressed when the power supply for the receiver isoff.

Then, the process of the CPU 41 starts from Step 101 in the routine 100of FIG. 2, it is distinguished in Step 102 whether or not the receiverpower supply is on, and since it is off in this case, the processproceeds from the Step 102 to Step 103. In this Step 103, a switchingcircuit 13 is connected to the microphone 12 side as shown in thefigure, and thereafter, the process proceeds to Step 111.

In this Step 111, it is distinguished by checking the table RECT whetheror not there is any area in the memory 22 which can be used forrecording. If there is the area, the process proceeds from Step 111 toStep 121. In the Step 121, by referring to the table RECT, a headaddress A ADRk (k=any of 1 to n) of the next area to an area having anewest, unreproduced matter recorded therein within the memory 22, isacquired like the head address of the remainder in the case of FIG. 6A.In this respect, if there is no unreproduced matter, the head address ofan area having, for example, an oldest, reproduced matter recordedtherein will be acquired.

Further, in the Step 121, by checking the table RECT, a number ofdivided areas usable for recording are converted to the period of timeduring which recording can be performed, and this period is onceretained in the RAM 43.

Subsequently, in Step 122, the control circuit 24 is instructed torecord from the start address A ADRk acquired in the Step 121, and therecording is started. More specifically, a command POWERUP for turningon the power supply is first supplied to the control circuit 24 to causethe recording/reproducing circuit 20 to be in an activated state fromthe standby state. Next, a command RECPWR to stand ready for recordingand the start address A ADRk acquired in the Step 121 are supplied, andthe recording/reproducing circuit 20 is caused to be in a standby statefor recording from the address A ADRk of the memory 22. Thereafter, acommand RECD to execute the recording is supplied. Therefore, therecording/reproducing circuit 20 starts recording from the address AADRk of the memory 22.

When you talk a matter or the like toward the microphone 21 at thistime, an audio signal from the microphone 21 is supplied to the memory22 through the switching circuit 13 and a low-pass filter 21, so that itis written from the address A ADRk one sample at a time in order, inother words, recorded.

During this period of time, the process in the CPU 41 proceeds to Step123 to compare, for example, the recordable time retained in the RAM 43by the Step 121 with time elapsed since recording by the Step 122 wasstarted, whereby it is distinguished whether or not there is still anydivided area usable for recording in the memory 22.

If there is a divided area usable for recording in the memory 22, theprocess proceeds from the Step 123 to Step 124, and in this Step 124, itis distinguished whether or not a reproduction/stop key K PB of theoperation keys K PW to K PB has been pressed. If not, the processreturns to the Step 123 from the Step 124.

Therefore, when recording is started by the Step 122, the Steps 123 and124 are repeated thereafter, and if the memory 22 has a divided areausable for recording and the reproduction/stop key K PB has not beenpressed, the recording will be continued. In this respect, the addressof the memory 22 is used in a ring shape during this recording.

When the divided area usable for recording is exhausted during thisrecording, this is distinguished by the Step 123, and the processproceeds from the Step 123 to Step 131. When the reproduction/stop key KPB is pressed during the recording, this is distinguished by the Step124, and the process proceeds from the Step 124 to the Step 131.

In the Step 131, the termination process for recording is executed. Morespecifically, a command STOP to stop the recording/reproducing operationis supplied to the control circuit 24, and then a command STOPPWRD toturn off the power supply is supplied. Accordingly, therecording/reproducing circuit 20 enters a standby state.

Further, in the Step 131, the head flag and the unreproduced flags ofthe table RECT are updated in accordance with use results of the dividedarea. Of the divided areas used for recording at this time, the headaddress A ADRk of the first area is stored in the memory 51 as the headaddress of the area having a newest, unreproduced matter recordedtherein.

Thereafter, the Step 132 terminates the routine 100 to enter a standbystate for the next process.

In this respect, in the Step 111, if the memory 22 has no area usablefor recording, the process proceeds from the Step 111 to Step 112. Inthe Step 112, a formation circuit 19 is driven to form a signal forerror noise, and this signal is supplied to an amplifier 15. From aspeaker 16, a beeping sound is produced as a warning notifying thatthere is no memory area in which recording can be performed. Thereafter,the process proceeds to Step 132 to complete the routine 100.

When the receiver power supply is off, pressing the recording key K REcauses a new matter to be recorded in an area contiguous to an areahaving a newest, unreproduced matter reported therein within the memory22. When a free area is exhausted in the memory 22, or when thereproduction/stop key K PB is pressed, the recording is terminated.

[Recording of Broadcast]

This is a case where a broadcast received by the reception circuit 11 isrecorded. In this case, the recording key K RE is pressed when thereceiver power supply is on.

Then, the process of the CPU 41 starts from the Step 101 of the routine100, and it is distinguished in the Step 102 whether or not the receiverpower supply is on. In this case, since the power supply is on, theprocess proceeds from the Step 102 to Step 104, and in this Step 104,the switching circuit 13 is connected to the reception circuit 11 sidecontrary to the figure, and thereafter, the process proceeds to the Step111.

Accordingly, thereafter, the broadcast is recorded as described in theabove-described [voice recording operator].

[Reproduction of Voice]

This is a case where a matter or broadcast recorded in accordance withthe above-described [Recording of Voice] is reproduced. In this case,the reproduction/stop key K PB is pressed whether the reciever powersupply is on or off.

Then, the process in the CPU 41 starts from the Step 201 of the routine200 in FIG. 3, and in the Step 202, the switching circuit 14 isconnected to the recording/reproducing circuit 20 side contrary to thefigure, and thereafter, the process proceeds to Step 211.

In this Step 211, it is distinguished by checking the table RECT whetheror not there is any unreproduced matter, and if there is, the processwill proceed from the Step 211 to the Step 221. In this Step 221, byreferring to the table RECT, the head address A ADRk of the oldest areais acquired from areas having unreproduced matters recorded thereinwithin the memory 22, like the head address of the area {circle around(3)} in the case of FIG. 6A.

Subsequently, in Step 222, the control circuit 24 is instructed toreproduce from the start address A ADRk acquired in the Step 221, andthe reproducing is started. More specifically, a command POWERUP to turnon the power supply is first supplied to the control circuit 24 to causethe recording/reproducing circuit 20 to be in an activated state fromthe standby state. Next, a command PLAYPWR to stand ready forreproducing and the start address A ADRk acquired in the Step 122 aresupplied, and the control circuit 24 is caused to be in a standby statefor reproducing from the address A ADRk of the memory 22. Thereafter, acommand PLAYDD to execute the reproducing is supplied. Accordingly, inthe recording/reproducing circuit 20, the reproducing is started fromthe address A ADRk of the memory 22.

When reproducing from the memory 22 is started, the audio signal issupplied to the speaker 16 through a signal line of a low-pass filter23, the switching circuit 14 and the amplifier 15. Accordingly,reproducing of the oldest, unreproduced matter is to be started withinthe memory 22.

During this period of time, the process in the CPU 41 proceeds to Step223, and in this Step 223, for example, waiting for 1 second isexecuted, and thereafter, the matter under the reproducing is regardedas “reproduced”.

Subsequently, the process proceeds to Step 224 in FIG. 4, and in thisStep 224, it is distinguished from the control circuit 24 whether or notdata EOM indicating that reproducing advanced up to the last address ofthe matter currently under reproducing has been outputted. If the dataEOM has not been outputted, the matter currently under reproducing iscontinuously being reproduced, and therefore, the process proceeds fromthe Step 224 to Step 225. In this Step 225, it is distinguished whetheror not the reproduction/stop key K PB has been pressed.

When the reproduction/stop key K PB has not been pressed, the processproceeds from the Step 225 to Step 226, and in this Step 226, it isdistinguished whether or not the plus key K+ has been pressed. If it hasnot been pressed, the process proceeds from the Step 226 to Step 227,and in this Step 227, it is distinguished whether or not the minus keyK− has been pressed. If it has not been pressed, the process returnsfrom the Step 227 to the Step 224.

When reproducing of the matter is started by the Step 222, thereproduced state of the matter is continued, and the processes in theSteps 224 to 227 will be repeated until the reproducing is terminated.

When the reproducing of the matter currently under reproducing advancesup to the last address, the data EOM indicating this advancement isoutputted from the control circuit 24, and this data EOM is detected byStep 224. The process proceeds from the Step 224 to Step 231, and inthis Step 231, a termination process for reproducing is executed. Morespecifically, to the control circuit 24, a command STOP to stop theoperation of recording/reproducing is supplied, and then a commandSTOPPWRD to turn off the power supply is supplied. Accordingly, therecording/reproducing circuit 20 enters a standby state. An unreproducedflag corresponding to the divided area used for the reproducing is setto “0”.

Subsequently, the process proceeds to Step 232, and the switchingcircuit 14 is connected to the reception circuit 14 side to terminatethe routine 200 by Step 233 thereafter. When the reproduction/stop key KPB is pressed, the oldest, unreproduced matter is reproduced, and whenthe reproducing of the matter is terminated, the process returns to thestate before this reproducing is executed.

When the reproduction/stop key K PB is pressed while the matter is beingreproduced and the Steps 224 to 227 are repeated, this is detected inthe Step 225, and the process proceeds from the Step 225 to Step 234. Inthe Step 234, a period of time since the reproducing was started by theStep 222 is converted into an address in the memory 22, and this addressis retained in the memory 51. Thereafter, the process proceeds to theStep 231 to terminate the routine 200 by the Step 233. Accordingly, ifreproducing is started from the address retained in the memory 22, evenif the reproducing is suspended midway, it will be possible to listen tothe follow-up.

Further, when the plus key K+ is pressed while the matter is beingreproduced and the Steps 224 to 227 are repeated, this is detected inStep 226, and the process proceeds from the Step 226 to Step 241.

In the Step 241, it is distinguished by checking the table RECT whetheror not the matter currently under reproducing is the newest one, and ifit is not the newest matter, the process proceeds from the Step 241 toStep 242 because there is a matter recorded next. In the Step 242, bychecking the table RECT, the head address of the next matter is fetched,this is set to the start address A ADRk, and thereafter, the processreturns to Step 222.

Therefore, since reproducing is started from the head address acquiredin the Step 242 thereafter, when the plus key K+ is pressed while acertain matter is being reproduced, it becomes possible to reproduce thenext matter to the matter under reproducing from the beginning.

In this respect, in the Step 241, if the matter currently underreproducing is a newest matter, the process proceeds from the Step 241to Step 243 because there is no matter recorded next. In this Step 243,by checking the table RECT, the head address of the matter currentlyunder reproducing is fetched, this is set to the start address A ADRk,and thereafter, the process returns to the Step 222. Accordingly, whenthe plus key K+ is pressed while the newest matter is being reproduced,it is possible to listen to the newest matter from the head again.

Further, when the minus key K− is pressed while the matter is beingreproduced and the Steps 224 to 227 are repeated, this is detected inthe Step 227, and the process proceeds from the Step 227 to the Step244.

In the Step 244, by checking the table RECT, it is distinguished whetheror not the matter currently under reproducing is the oldest matter, andif it is not the oldest matter, the process proceeds from the Step 244to the Step 245 because there is a matter recorded before it. In theStep 245, by checking the table RECT, the head address of the previousmatter is fetched, this is set to the start address A ADRk, andthereafter, the process returns to the Step 222.

Accordingly, since reproducing is started from the head address acquiredin the Step 245 thereafter, when the minus key K− is pressed while acertain matter is being reproduced, a matter previous to the matterunder reproducing can be reproduced from the beginning.

In this respect, in the Step 244, if the matter currently underreproducing is the oldest one, the process proceeds from the Step 244 tothe Step 243 because there is no matter recorded before it, the headaddress of the matter currently under reproducing is set to the startaddress A ADRk, and thereafter, the process returns to the Step 222.Accordingly, when the minus key K− is pressed while the oldest matter isbeing reproduced, it is possible to listen to the oldest matter from thehead again.

Further, in the Step 211, if there is no unreproduced matter, theprocess proceeds from the Step 211 to the Step 212. In this Step 212,the address retained by the Step 234 is fetched from the memory 51, thisis set to the start address A ADRk, and thereafter, the process proceedsto the Step 222. Therefore, the matter whose reproducing was suspendedlast time will be able to be reproduced from the portion at which thereproducing was suspended.

[Summary]

As described above, according to the receiver of FIG. 1, a matter can berecorded and reproduced using the memory 22, and in this case,particularly according to the above-described receiver, overwriterecording on an unreproduced matter is prohibited and reproducing isarranged to be started from an unreproduced matter in accordance withthe idea that the user listens to, at least once, a matter oncerecorded. Therefore, the user can surely listen to the matter oncerecorded only by pressing the reproduction/stop key K PB.

As regards a matter once reproduced after recording, overwrite recordingthereon is allowed, and since the address of the memory 22 is madering-shaped, recording can be performed by making full use of the areafor the memory 22 even if any unnecessary recording is not erased.

Further, since it is not necessary to manage by assigning a number toeach matter recorded among others, it is possible to perform recordingand reproducing only by the use of the recording key K RE and thereproduction/stop key K PB, and the operation is very simple and easy.

In this respect, in the foregoing, the address management method for thememory 22 can be changed in accordance with the standards orspecifications of the memory 22 and the control circuit 24. For example,even in the case of the above-described memory 22 and control circuit24, it is also possible to store the start address and terminationaddress in the memory 51 for each matter recorded for management, and inthis case, since when the recording is terminated, this is indicated bythe data EOM, the period of time used for the recording can be convertedinto a termination address for writing.

According to the present invention, the user can certainly listen to anymatter once recorded only by a keying operation for reproducing even ifthe matter is not selected. Also, it is possible to make full use of thememory area for recording even if any unnecessary recording is noterased. Further, it is possible to perform recording and reproducingonly by a keying operation for recording and reproducing, and theoperation is very simple and easy.

What is claimed is:
 1. A recording/reproducing apparatus, comprising: afirst IC memory wherein operations for writing/reading of an audiosignal are performed; a control circuit for controlling saidwriting/reading of said audio signal to/from respective addresses withinsaid first IC memory, wherein said addresses are arranged in a ringshape; system controlling means for automatically writing, when arecording key thereof is pressed by a user of the apparatus, a firstaudio signal starting at an address succeeding an area within said firstIC memory wherein a newest and unread audio signal has been stored, andfor automatically reading, when a reproduction key is pressed by theuser, a second audio signal from a head address of a predetermined areawherein an oldest and unread audio signal has been stored within saidfirst IC memory, wherein a nonvolatile memory is included in said firstIC memory to preserve said audio signal written therein, and said systemcontrolling means stops said reading of said second audio signal whensaid reading of said second audio signal from said predetermined areawithin said first IC memory is completed, and said system controllingmeans sets said predetermined area to a read area; and a second ICmemory for storing a management table for managing said memory addresseswithin said first IC memory at respective divided areas, wherein saidmanagement table includes for each of said respective divided areas ahead address of said divided area, a head flag for indicating that saiddivided area is a first area for said writing of said audio signal, andan unreproduced flag for indicating whether said divided area has beenreproduced.